The invention relates to a dispenser for flowable media, particularly an atomizer, with a media reservoir located in a casing and with a thrust piston pump, which is provided with a pump piston displaceably guided on a piston path of a pump cylinder between a starting position and a pump stroke end position, as well as a pump chamber formed by the pump cylinder and connected to a discharge opening of the dispenser by means of an outlet duct, which is in the form of a dosing chamber determining the discharge volume for each complete pump stroke.
Known dispensers or delivery devices of this type have a media reservoir spatially separated from the pump chamber connected to said pump chamber by means of an inlet duct with a generally connected in intake valve and which feeds medium into the pump chamber during the pump piston return stroke. However, this makes such dispensers unsuitable for those applications in which, such as for a medical disposable syringe, only a single charge of an e.g. pharmaceutical medium is to be delivered and then the discharge device is, instead of being used again, thrown away, e.g. for hygienic, therapeutic or safety reasons.